Graphene is a one-atom thick planar sheet of sp2-bonded carbon atoms. Theoretically, graphenes having a perfect hexagonal network structure can be densely stacked to form a layered structure exhibiting superior stability and superior thermal conductivity in electronics. Owing to the superior physical properties, graphene can be widely applied to various devices, promoting the performance of electric conduction, thermal conduction, or strength of the devices. However, the related industry has not yet been able to efficiently mass-fabricate highly-graphitized graphene since physicists separated graphene from graphite at the beginning of the new millennium. The conventional graphene mass-fabrication technology uses high temperature and high pressure to rearrange carbon atoms of graphite into a planar hexagonal network structure. However, the conventional technology is hard to achieve a greater extension in the planar direction (La) of the hexagonal network structure of graphene. Further, the hexagonal network structure is normally imperfect. Thus, the interplanar distance (d(0002)) between the graphene planes is much larger than the theoretical value. Consequently, the physical properties of the graphene fabricated by the conventional technology are unlikely to meet expectations.
The Inventors had disclosed methods for fabricating highly-graphitized graphene platelets in Taiwan patents No. 201022142 and No. 201131019, wherein high-purity graphite is catalyzed by a metal catalyst to rearrange carbon atoms into a perfect planar hexagonal network structure, whereby is obtain a highly-graphitized graphene platelet. However, the abovementioned methods are unlikely to mass-fabricate commercial graphene platelets. In practical applications, what various electronic devices need are the physical properties of graphene platelets. It should be a preference that the mass-fabricated highly-graphitized graphene is separated into single-layer or multi-layer graphene platelets before their application. In the conventional technologies, graphite is normally separated into a plurality of single-layer or multi-layer graphene platelets in an explosion method or a chemical-exfoliation method. However, the abovementioned conventional technologies would damage the planar hexagonal network structure of graphene platelets and degrade the physical properties thereof. Therefore, the conventional technologies cannot fabricate large-area graphene platelets having a perfect planar hexagonal network structure, not to mention fabricating them in high efficiency.
Accordingly, the field concerned is eager to develop a method for fabricating a large-area graphene platelet having a perfect planar hexagonal network structure to facilitate the application of graphene and the growth of the related industry.